start messing about with timeline manager

internal/processing/timeline/sharedpool.go

@@ -0,0 +1,46 @@
+package timeline
+
+import (
+	"sync"
+	"time"
+)
+
+type sharedCache struct {
+	data      map[string]*post
+	maxLength int
+	*sync.Mutex
+}
+
+func newSharedCache(maxLength int) *sharedCache {
+	return &sharedCache{
+		data:      make(map[string]*post),
+		maxLength: maxLength,
+	}
+}
+
+func (s *sharedCache) shrink() {
+	toRemove := len(s.data) - s.maxLength
+	if toRemove > 0 {
+		s.Lock()
+		defer s.Unlock()
+		oldest := time.Now()
+		oldestIDs := make([]string, toRemove)
+		for id, post := range s.data {
+			if post.createdAt.Before(oldest) {
+				oldest = post.createdAt
+				oldestIDs = append(oldestIDs, id)
+			}
+		}
+
+	}
+}
+
+func (s *sharedCache) put(post *post) {
+	s.Lock()
+	defer s.Unlock()
+	s.data[post.statusID] = post
+}
+
+func (s *sharedCache) get(statusID string) *post {
+	return s.data[statusID]
+}